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How about getting the 95% 2 stage variable speed propane furnace and having the heat strip installed at the same time. The oil furnace is atleast 15 years old. The variable speed blower seems like it would help with savings and comfort. Want to have a plan before I get estimates and can ask about the 3 stage deal when I call. Something needs done $1600+ for heat sucks.

I'd go all electric with latest Heat Pump WHEN the furnace dies. +++ WHY would one buy a High efficiency LP if use is going to be minimal.?

Designer Dan
It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE
Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

To perform an accurate economic analysis I would need temperature bin data for your locale.
It's a bit of an effort to derive this data from the Weather Channel information on daily high/lows.
What is a 'major' city that is close ( 40 miles or so)?

I set the switchover to 25, last night it got that cold,tstat is set to 71, this morning it said inside temp 69. So 30 is lowest the 2.5 ton will keep up with.

If you had an IAQ stat. I'd set the heat pump lock out to 25 and teh furnace lock out to 30, and use balance point plus 2° droop. To allow the heat pump to run during the day when its 25 outside, but have the furnace take over when it lost 2 degrees at night time.

If you had an IAQ stat. I'd set the heat pump lock out to 25 and teh furnace lock out to 30, and use balance point plus 2° droop. To allow the heat pump to run during the day when its 25 outside, but have the furnace take over when it lost 2 degrees at night time.

Can the HW 8320 be set to do that? If not I am going to leave it set to 25 for now, if we lose a couple degrees at night we can live with it, should be warming up soon. Want to avoid burning anymore oil at $4 a gallon

3-ton heat pump with 3 kW heat strip, the House- Heat pump total electric SYSTEM would be adequate down to 15'F.
Oil use at temperatures < 15'F ought to be < 100 gallons.

Propane at $2.17 / gallon, 90% efficient is $2.54 / 100,000 BTU/Hr ( therm)
Electric at $0.10/ kw-hr down to ~20'F would be $1.25 / therm or half of propane.

What about putting in a 2-stage heat pump large enough to heat down to 15 on it's own and run ac on low stage? Don't want to change out my HP right now, but would something like that work or maybe a dumb idea?

have you considered a single stage 95% efficient furnace with a high efficent (x13) motor .or a two stage furnace with a varible speed motor then when and if you wanted you could go to a two stage heat pump

#2 @ 80% costs you $35 ? million BTUs, Porpane @ 90% costs you $27 / million BTUs
400 gal;lons are 54 million BTUs with $5 savings $ saves you $270
What would you spend to save $270 ?
Don't know where you live but your heat bill sounds pretty good to me

GAs or propane short cycling is not as bad (inefficient) as oil, short cycling Might be a factor or Hot water or air system, or domestic hot water is ?

You have got to learn from other people's mistakes! Because God knows you don't live long enough to make them all yourself !!!!!!!!

#2 @ 80% costs you $35 ? million BTUs, Porpane @ 90% costs you $27 / million BTUs
400 gal;lons are 54 million BTUs with $5 savings $ saves you $270
What would you spend to save $270 ?
Don't know where you live but your heat bill sounds pretty good to me

GAs or propane short cycling is not as bad (inefficient) as oil, short cycling Might be a factor or Hot water or air system, or domestic hot water is ?

The calculations I have seen and done look more like $4-$500 in savings between propane and oil. I do understand that the prices will change wich makes the decision harder. I didn't think my heat bill was good at all $1600 for oil plus what electric the hp uses, we don't have a big house. I like the idea of adding a heat strip to help the hp down to 15 like dan sw fl said but then others say the electric heat is never satisfied and not comfortable.